Apparatus for smoke abatement and by-products recovery



May 8, 1956 J. VAN VLIET 2,744,737

APPARATUS FOR SMOKE ABATEMENT AND BY-PRODUCTS RECOVERY Filed Dec. 17,1952 2 Sheets-Sheet 1 "3 IN VEN TOR.

JEJHN WVZIEJ J. VAN VLlET May 8, 1956 APPARATUS FOR SMOKE ABATEMENT ANDBY-PRODUCTS RECOVERY Filed Dec. 1'7, 1952 2 Sheets-Sheet 2 IN V EN TOR.jomv Wzv %ET flu? United States Patent APPARATUS FOR SMOKE ABATEMENT ANDBY-PRODUCTS RECOVERY John Van Vliet, Chicago, Ill.

Application December 17, 1952, Serial No.'326,446

6 Claims. (Cl. 261-91) This invention relates to apparatus forrecovering air-' borne solids which are the by-products of combustionresulting from the burning of oil, coal, or other hydrocarbon fuels forthe dual purposes of diminishing air pollution and for the recovery ofthe airborne particles.

A principal object of the present invention is to provide an inexpensiveyet highly eflicient exhaust gas cleansing and purifying apparatusadaptable to both domestic as well as industrial application for abatinghealth hazard and contamination which are characteristic of the smokefumes discharged by various types of combustion systems.

Another object of the present invention is to provide an apparatus forseparating and collecting airborne solids from the discharge flues ofcombustion systems in a manner of recovery'which will accomplishefllcient accumulation of such particles in concentrated form, afterwhich they may be variously processed for difl'erent purposes ofeconomic utilization.

Still another object of the present invention is to provide an apparatusfor the recovery of solids from corn bustion system smoke discharge bythe sole use of water as a trapping agency under conditions which willpermit the repeated re-use of the water over repeated operations andwithout incurring waste such as is incident to conventional structuresof water spray apparatus.

For a better understanding of the foregoing and other objects andpurposes of this invention as will later appear, reference will now behad to the following detailed description, as well as to theaccompanying drawings, in both of which like reference numeralsdesignate corresponding parts throughout, and in which:

Fig. 1 is a plan view with parts broken out of a multiple unit filterapparatus for smoke abatement embodying certain features of the presentinvention;

Fig. 2 is a side elevational view of the apparatus illustrated in Fig. 1with various portions broken away and in section;

Fig. 3 is a fragmentary perspective view of certain of the structuralelements disposed in the interior of one of the filter units, and

Fig. 4 is a transverse sectional view on an enlarged scale takenapproximately on line 44 of Fig. 1.

Referring now more particularly to the accompanying drawings, thereference numeral 11 designates an inlet flue which may be connectedwith a chimney or fire chamber exhaust conduit of a hydrocarboncombustion apparatus whose smoke is ordinarily beset with certainundesirable airborne particles commonly identified as soot, fly ash,etc. From its source of generation the smoke is directed downwardlythrough the flue 11 into a preliminary expanding chamber 12, which,because of its larger cross section affords a momentary check upon thedown draft velocity while at the same time the gases are permitted tospread laterally throughout the full width afforded by the firstfiltering unit 13. Under this action the more massive airborne particlesexperience a centrifuge effect and seek to plunge downward.

A draft action is induced forcibly throughout the train of units byreason of a centrifugal fan 14 driven by an electric motor 15 which islocated at the egress end of the filtration system and identified withthe exhaust flue 16 which communicates with a header chamber 17 locatedat the rear of the third, and in the instant embodiment, final one of aseries of filtering units designated 18.

Also, in the instant embodiment three successive filtering unitsdesignated 13, 19 and 18 operate successively upon the gaseous dischargefumes as they thread from right to left in the arrangement viewed inFigs. 1 and 2. The number of such units which are to be employed intandem is dependent upon several considerations, such as the precisenature of the hydrocarbon fuel, or in other words, the density of itsdischarge fumes, as well as upon the degree of purification andparticles recovery which it is desired to attain. For some purposes asingle filtration unit may be adequate, and for many purposes willcomply with minimum standards of purification. It is to be recognized,therefore, that other than as an indication of the feasible andpractical manner to which the present invention lends itself to anarrangement in tandem, the number of such units is purely a matter ofdesigning and may be left to particular choice or preference.

Each one of the filtering units 13, 19 and 18 consists essentially of asubstantially equilateral trapping chamber 21 defined by thelongitudinal side walls 22 and 23 which extend throughout the series orbattery of filters, the end walls 24 and 25 which define the extremitiesof the unit and the intermediate barrier or bafile walls 26 and 27. Asthe flue gases are directed downwardly through the pipe 11 and expanderchamber 12, they encounter a series of angularly disposed baffles 28, 29and 31, Figs. 1 and 2. These, after the manner best indicated in Fig. 2,extend transversely across the width of the unit 13, causing theairstream to be deflected leftwardly at the same time that it encountersa series of liquid umbrella syrays generally indicated at 32 and 48.These liquid sprays hereinafter described are generated by a rotaryturbine 33, the unique performance and operation of which will bedescribed later, and the effect of which is to dispose a series ofcentrifugal spray discharges at different levels whereby there isincreased the probalility of encounter and wetting of airborne particlescarried by the flue discharge airstream.

The effectiveness of entrampment and precipitation of the particles hasbeen found to be materially or substantially enhanced by the provisionof the angularly disposed baflles 2831, and in cooperation with thevapor part, it has been found that these frothy accumulations retaintheir flotation characteristics indefinitely so that they may be drawnoff the surface by any suitable drainage or separation method.

For these reasons it is said that the present filtration and trappingmethod is one that is operative without perceptibile water consumptionbeyond that which is incident to evaporation or that lost throughvehicular dissipation as the froth accumulation is periodically removed.

The rotary impellers 33 are vertically journaled on.

shafts 34 and may be driven independently by individual motors as shownat 40 or in unison from any suitable driving source at a rotary speed ofapproximately 1750 R. P. M. in a counterclockwise direction, as viewedin Fig 1. Each turbine or impeller 33 is inverted conical member forrhedof sheet or thin metal and supported upon spiderelements 35 and 36 attop and bottom, as maybe observed from Figs. 3 and 4. Where the conicalelements 33 impinge upon the circumferential limbs of spider elements 35and 36, they may be secured by soldering or riveting. The angular slopeof the conical elements is about 15 from vertical, and at spacedintervals along elemental lines there is secured to their outer surfacea series of tubular spray elevators or lift tubes designated 37,38 and39.

in the preferred illustration the elevator tubes are shown to be ofthree different classes according to their relative disposition,although it is to be understood that this distribution is a matter ofarbitrary arrangement and that their number, according to class, may bemoderately varied, and also that their total number respecting each inrotor 33 may also be moderately varied. At their lower extremities thetubular scoops 3739 are cut on a bias, as best indicated in Fig. 4 at41. This presents a larger intake area foremost in the direction ofencounter with the bath water, and since each of the elevator tubes isimmersed below the surface of the bath 34, it will gather a column ofwater, and, under the indicated velocity, eject a spray at its upperterminal 42, which thus liberated will be hurled centrifugally to formthe already described umbrella pattern at its respective elevation.

By repeating the stagger of elevator tubes as indicated in Fig. 2throughout the periphery of each impeller 33 the concentration of waterspray at each umbrella level may be made suificiently dense so that thetotal barrier effect which is presented to the air stream at each areaof intersection will preclude any possibility of escape. A singlefiltration unit such as that designated 13 in which the base diameter ofthe spray rotor 33 is about fourteen inches operating in conjunctionwith an oil fire exhausted through a twelve-inch flue under the statedspeed of rotation has been observed to eliminate 92% of the recoverablesolids, including fly ash and soot, under a single exchange pass with anoperating unit patterened in accordance with the accompanyingillustrations.

Each rotor 33 is driven by its vertical spindle shaft 34 in acounterclockwise direction, as observed in Figs. 1 and 3. Its rotationis prevented from setting up a swirl condition in'the water bath 34 byan arrangement of vertical breakers or partitions all, 412, 43 and 44,which extend radially from the axis of rotation, as best indicated inFig. 3. As a consequence of such rotation, however, each one of thetubular elevators 3739, because of its obliquely presented apertures4'7, scoops up a continuing column of water ejecting it at its upperegress 45 with a constant centrifugal trajectory.

Also, a cylindrical column of water will be frictionally generated toclimb the interior surface 46 of each conical element 33. This water,aided by the inclination of the conical wall surface, will climb untilit reaches the uppermost edge of its conical element 33, and there behurled in a similar horizontal trajectory along a line such as that.designated 48, also forming an umbrella pattern, and constituting awater barrier against which the airborne stream of solids is assuredencounter by a high degree of probability.

With respect to any of the airborne particles which survive encounter bywater issuing through the umbrella patterns 32 or 48 in the downdraftportion of its travel in unit 13, a second opportunity for suchencounter is afforded in the region of the secondary baflie plates 51,52 and5'3, which are disposed and shaped in the manner in which they areillustrated in Eigs. 'Z and 3. Bafile 51 is disposed transversely ofunit 13cm about a 38 slope from h er ca nd s de i ned o impar an up aand l ward direction to the air stream after it has passed the region ofthe turbine or rotor. Thereafter, baffle 52, being somewhat crowned orcurved inwardly, is designed to cooperate with baffle 53 to set up alocal rotary eddy current designed to capture straying solids particlesdur ing the upstream portion of their travel, and to revert them intothe path of the trajectory lines 32 and 48. Meanwhile, certain portionsof the air stream which follow more closely the principal path ofcurvature parallel to the bonnet 55 will be directed to enter upon arepetition of the aforedescribed treatment under the effect of theintermediate filtering station 19.

It is to be noted that substantially all of the water spray which islifted by the elevator tubes 37-39, as well as that which is distributedby the centrifugal action of the conical surface as, returns to the bath34 and is subject to re-use under conditions of continuous cycling.Periodically, the surface accumulation of carbon and soot particles maybe drawn off as through a drainage cock 53, Pig. 2, located at one endof the fitering assembly, and thereafter replenishing water may besupplied from any appropriate source, as through an intake 59 at theother end. Notwithstanding the barriers 26 and 27 which separate theseveral units, the water in the bath 34 is preferablyintercommunicativc, and toward this end apertures 61 in the submergedportion of the barriers 26 and 27 provide continuous communicationbetween the water levels which are otherwise partitioned from oneanother.

In summarizing, it is called to attention that in accordance with thepresent invention there is afforded a simple and unique gas filteringapparatus which lends itself to be employed singly or in tandem, andwhich utilizes as purging agency for solids-laden gases, such ascombustion smoke, etc., the filtering principles of plunging draft, eddycurrent turbulation, and contemporaneously therewith, a high trajectorymultiple-level water spray generated simply and. efficiently from areusable reservoir fount.

While the present invention has been explained and described withreference to various particular contemplations of structural details, itwill be understood nevertheless that numerous changes and modificationsare susceptible of being incorporated without departing from theessential spirit or scope thereof. Accordingly, it is not intended to belimited by the features illustrated in the accompanying drawings nor bythe language employed in the foregoing description except as indicatedin the hereunto appended claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is as follows:

1. Apparatus for separating particles suspended in a gaseous mediumwhich comprises a vertical duct for flow of the medium and particles;means defining a separating chamber; a plurality of baffle means mountedin said chamber at varying angles,said baffie means having activedeflecting surfaces disposed substantially normally to the direction offlow of the gaseous medium; a slinger in said chamber mounted forrotation on a vertical axis; means for rotating said slinger; areservoir for liquid, said slinger being partially immersed in theliquid in the reservoir whereby liquid may be withdrawn therefrom by theslinger and discharged as a substantially horizontal sheet of highvelocity droplets intersecting the direction of flow of the medium andimpinging on the said baffie surfaces, whereby an intimate permeation ofthe medium by the liquid is achieved and the. particles driven out ofthe medium, and an outlet duct in communication with said chamber.

2. The combination, as set forth in claim 1, in which said slingercomprises a. conical surface with its apex directed downwardly andcarrying a plurality of openended tubes for lifting the liquid from anintake level to a discharge level.

3. The combination set forth in claim 2, in which said tubes have theirrespective exit ends at difiering elevations.

4. Apparatus for separating particles suspended in a gaseous medium,which comprises a vertical duct for flow of the medium and particles;means defining a separating chamber; a plurality of baffle means mountedin said chamber at varying angles, said baflie means having activedeflecting surfaces disposed substantially normally to the direction offlow of the gaseous medium; a slinger in said chamber mounted forrotation on a vertical axis; means for rotating said slinger; areservoir for a liquid, said slinger being partially immersed in theliquid in the reservoir, whereby liquid may be withdrawn therefrom bythe slinger and discharged as a substantially horizontal sheet of highvelocity droplets intersecting the direction of the flow of the mediumand impinging on the said bafiie surfaces, whereby an intimatepermeation of the medium by the liquid is achieved and the particles'driven out of the medium; an outlet duct in communication with saidchamber; and a second plurality of baflies, said baffles having activesurfaces disposed substantially normally to the direction of flow,disposed in said chamber adjacent said outlet duct.

5. Apparatus for separating particles suspended in a gaseous medium,which comprises an inlet duct for passage of the medium and particles;means defining a separating chamber; a plurality of bafiie means mountedin said chamber at varying angles having deflecting surfacessubstantially normal to the direction of the flow of the gaseous medium;a slinger arranged in said chamber; means for rotating said slinger; areservoir for liquid; means for transferring liquid from thereservoir tothe surface of the slinger from which surface the fluid is discharged inhigh velocity droplets into the chamber, through the stream of themedium and against the said bafiie surfaces to effect an intimate,vigorous permeation of the medium by the fluid to drive the suspendedparticles thereoutof; an outlet duct leading from said chambet for exitof the particle-free medium, said outlet duct having a second pluralityof baflies, having active surfaces disposed substantially normally tothe flow of medium disposed in said chamber adjacent said outlet duct.

6. Apparatus for separating particles suspended in a gaseous mediumwhich comprises an inlet duct; an outlet duct substantially parallel tosaid inlet duct; means defining a chamber joining said ducts whereby themedium passes from the inlet duct into the chamber in a rightangledstream; bafiie means positioned in the zone of juncture of the inletduct and chamber having active surfaces substantially normal to the flowof the medium; means for projecting fluid droplets at high velocityintersecting and through the entering stream for impingement againstsaid baffle surfaces; means for conducting said medium in a right-angledstream toward the outlet duct after said medium has been firstintersected; a second baifie means positioned in the zone of juncture ofthe outlet duct and chamber, said second battle means having activesurfaces substantially normal to the flow of the medium; means forprojecting fluid droplets at high velocity intersecting and through theoutgoing stream for impingement against said second bafile means,efiecting thorough permeation of the stream while in the chamber todrive the particles therefrom before exiting.

References Cited in the file of this patent UNITED STATES PATENTS

